The present invention relates to a novel digital mixer which is capable of monitoring multi-channel surround signals.
Audio mixing consoles have been known which are operable to adjust levels and frequency characteristics of audio signals input from many microphones or electric or electronic musical instruments, mix the thus-adjusted audio signals into several mixed audio signal groups, and deliver the mixed audio signals groups to power amplifiers. Generally, a human operator of the mixing console adjusts respective tone volumes and colors of audio signals representative of musical instrument tones and/or singing voices to conditions that appear to most appropriately express a performance, by manipulating various panel operators provided on the mixing console. The mixing console includes, as a signal input section of the console, a plurality of input channels for inputting signals from a plurality of microphones and other external equipment (microphone/line input signals), and the signal input section is programmed to perform a mixing process on the input signals in a desired manner and pass resultant mixing-processed signals to a plurality of output channels constituting a signal output section of the console. Generally, the signals of the individual input channels are amplified by head amplifiers and then delivered to a mixing processing section that adjusts respective frequency characteristics and levels of the signals and then mixes the signals in programmed combinations. After that, each of the thus-mixed signals is set to a desired output level via an output fader and then passed to any one of the output channels.
Typically, such mixing consoles are employed in theaters and concert halls and also used in recording studios to produce music sources for recording onto compact disks (CDs), DVDs, etc. For example, in the case of the mixing console used in a recording studio, tones performed by musical instruments and singing voices are input as initial mixing materials to be processed by the console. The mixing console adjusts the levels and frequency characteristics of a multiplicity of audio signals externally input via the microphones and mixes the thus-adjusted signals in desired combinations. Then, the mixing console adjusts the levels of the mixed signals and outputs the thus level-adjusted mixed signals. There have been known digital mixers that use DSPs and the like to digitally perform the mixing processing in such mixing consoles.
Generally, in theaters and the like, a plurality of speakers are placed at front and rear positions (i.e., in front of and in back of audience seats) in order to produce a sound field affording a high sense of presence or realism to the audience. Systems for producing such a high sense of presence or realism are commonly called “surround systems”. Most of the known digital mixers too are constructed to produce, as music sources to be recorded (i.e., recording music sources), mixing-processed signals that can attain a surround effect using any desired one of various surround modes, several of which are illustratively shown in FIGS. 10A to 10F.
The surround mode shown in FIG. 10A is a “stereo” mode, where left and right front speakers L, R are placed to achieve a sense of realism. The surround mode shown in FIG. 10B is a “(2+2)-channel” mode, where left and right front speakers L, R and left and right rear speakers Ls, Rs are placed to achieve a sense of realism. Further, the surround mode shown in FIG. 10C is a “(3+1)-channel” mode, where left, center and right front speakers L, C, R, and one center rear speaker S are placed to achieve a sense of realism.
Furthermore, FIG. 10D shows a “5.1-channel” mode, where left, center and right front speakers L, C, R, and left and right rear speakers Ls, Rs are placed, with a woofer speaker LFE placed at a suitable position, to achieve a sense of realism. FIG. 10E shows a “6.1-channel” mode, where left, center and right front speakers L, C, R, and left, center and rear speakers Ls, Cs, Rs are placed, with a woofer speaker LFE placed at a suitable position, to achieve a sense of realism. Furthermore, FIG. 10F shows a “7.1-channel” mode, where left, center and right front speakers L, C, R, left-center and right-center front speakers Lc, Rc, and left and right rear speakers Ls, Rs are placed, with a woofer speaker LFE placed at a suitable position, to achieve a sense of realism. In the following description, the surround modes of FIGS. 10B to 10F, other than the surround mode of FIG. 10A, are also referred to as multi-channel surround modes.
To localize a sound image at a predetermined position in a particular surround mode selected from among the above-mentioned various surround modes, it has been conventional to supply the installed speakers with surround signals having been adjusted to levels corresponding to the selected surround mode and predetermined localizing position. Although the conventional digital mixers are equipped with the above-mentioned surround modes, they can not produce output for monitoring surround signals in any of the surround modes having a greater number of channels than the stereo mode. Thus, the conventional digital mixers have been unable to monitor the surround signals to be used as the initial mixing materials and the surround signals to be used as the recording music sources.